Development of Bioadhesive Transdermal Patches of Bupivacaine for the Enhancement of Anaesthetic Effect: Study in Rat Model

Abstract

The topical route for local anaesthesia including ointments and creams can be easily washed off by wetting agents or with contact or movement. The goal and objective of the present study was to develop and formulate a transdermal patch for local anaesthesia. These patches were formulated by solvent casting method by the use of Hydroxypropyl Methylcellulose (HPMC) polymer, different enhancers, and vasoconstrictor which is the key ingredient for enhancing aesthetic activity. Formulated patches were evaluated for the physical and physicochemical parameters like moisture content, moisture uptake, folding endurance, water vapour permeability, drug content, and drug release, and in vivo study was done on rats. Amongst all the formulations, F7 was considered the ideal formulation which is the combination of HPMC polymer, polyoxyethylene 2-oleyl ether as an enhancer, and vasoconstrictor Tetrahydrozoline. For in vivo testing Tail flick method was applied and the effect of anaesthesia was maximum as compared to other formulations. In comparison to the control formulation, there was a 2.34-fold increase in aesthetic activity. When compared to the control formulation, the F7 formulation exhibited improved and longer efficacy. A transdermal bupivacaine patch incorporating a penetration enhancer and a vasoconstrictor could be created to improve the local cosmetic effects of bupivacaine.